Kind of a cheap answer but if we’re talking Linux/Windows and you intend to host Jellyfin in the future anyway, you could just spin it up on your machine. That way you can already familiarise with it.
Otherwise, I’d recommend to just maintain a sane file structure (which you’d later need for Jellyfin anyway, and probably for sanity also) and then watch/hear it with VLC. I believe VLC even supports some form of library management, but I have not used it, yet. It definetly supports queues.
On which device?
Kind of a cheap answer but if we’re talking Linux/Windows and you intend to host Jellyfin in the future anyway, you could just spin it up on your machine. That way you can already familiarise with it.
Otherwise, I’d recommend to just maintain a sane file structure (which you’d later need for Jellyfin anyway, and probably for sanity also) and then watch/hear it with VLC. I believe VLC even supports some form of library management, but I have not used it, yet. It definetly supports queues.